1. Field of the Invention
The present invention relates to a method of manufacturing a high-temperature superconducting winding, and, more particularly, to a method of manufacturing a continuous disk winding for high-voltage superconducting transformers that has special features of no joint and low loss, which are advantages of a layer winding, while being formed in the shape of a disk winding, which is advantageous in voltage distribution and insulation.
2. Description of the Related Art
Transformers are being recognized as the first application that can be put to practical use among currently developed high-temperature superconducting power equipment. Most high-temperature superconducting transformers recently researched and developed domestically and abroad are based on high voltage and large capacity. Depending upon the shape of winding, a high-temperature superconducting winding constituting such high-temperature superconducting transformers is generally classified as a solenoid type layer winding as shown in FIG. 1A or as a disk winding, which is widely adopted as a winding using a high-temperature superconducting wire made of a general tape formed in double pan cake type, as shown in FIG. 1B. The winding shape of most high-temperature superconducting transformers currently developed all over the world is the layer winding. On the other hand, the disk winding has not been much developed. This is because alternating current loss is less when the winding of the same high-temperature superconducting transformer is manufactured in the shape of the layer winding than when the winding of the same high-temperature superconducting transformer is manufactured in the shape of the disk winding.
For a superconducting wire used in developing the high-temperature superconducting power equipment, alternating current loss is generated due to an alternating magnetic field. Especially, the superconducting wire is very weak with relation to the magnetic field applied perpendicular to the surface of the superconducting wire. For this reason, it is a general trend to adopt the high-temperature superconducting winding manufactured in the layer shape in order to reduce loss and prevent decrease of efficiency.
In the case of the high-voltage transformer, the layer winding reduces the alternating current loss generated in the superconducting wire. However, the layer winding is disadvantageous in the terms of insulation. Furthermore, the capacitance of the high-voltage transformer is small, and therefore, the high-voltage transformer is vulnerable to voltage spikes. For this reason, the high-voltage transformer using a copper wire uses the disk winding.
The disk winding is more advantageous, in terms of voltage distribution and insulation, than the layer winding as the terminal voltage of the transformer is increased. In a transformer, to which high voltage is applied as in a power-transmission transformer, it is generally preferable to adopt the disk winding. In the case that the disk winding is applied to the high-temperature superconducting transformer, however, it is necessary to electrically connect the disks with each other, and a great loss is generated in such electrical connections. Consequently, the stability of the superconducting winding is reduced, and it results in high costs to cool the high-temperature superconducting transformer.
In spite of the above-mentioned drawbacks, however, the adoption of the disk winding as the winding for high-temperature superconducting transformers is urgently requested considering high voltage, which is a current trend of developing the high-temperature superconducting power equipment.